/*
 * [The "BSD license"]
 *  Copyright (c) 2013 Terence Parr
 *  Copyright (c) 2013 Sam Harwell
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
using System.Collections.Generic;
using Antlr4.Runtime.Sharpen;
using Antlr4.Runtime.Tree;

namespace Antlr4.Runtime.Tree.Xpath
{
    public abstract class XPathElement
    {
        protected internal string nodeName;

        protected internal bool invert;

        /// <summary>
        /// Construct element like
        /// <c>/ID</c>
        /// or
        /// <c>ID</c>
        /// or
        /// <c>/*</c>
        /// etc...
        /// op is null if just node
        /// </summary>
        public XPathElement(string nodeName)
        {
            this.nodeName = nodeName;
        }

        /// <summary>
        /// Given tree rooted at
        /// <paramref name="t"/>
        /// return all nodes matched by this path
        /// element.
        /// </summary>
        public abstract ICollection<IParseTree> Evaluate(IParseTree t);

        public override string ToString()
        {
            string inv = invert ? "!" : string.Empty;
            return GetType().Name + "[" + inv + nodeName + "]";
        }
    }
}
